"Mr PM, you tried to give a clean chit to Quattrocchi", BJP spokesperson Ravi Shankar Prasad told reporters here adding this has been found to be false by an income tax tribunal which said that kickbacks of Rs.41 crore were paid to Quattrocchi and Win Chaddha in the controversial Howitzer gun deal.

The principal opposition used Singh's recent statement that Ceasar's wife should be above suspicion to attack him for defending Quattrochi.

"His comment exonerating Quattrochi having been found to be false by a competent Tribunal. Would the Prime Minister now stand up to his own benchmark and apologise to the nation ? Prasad asked.

Prasad referred to Singh's remarks that "It is not a good reflection on the Indian legal system that we harass people and that Quattrocchi case is an embarrassment for the Government of India."

Taking on the Prime Minister, Prasad alleged that the Congress-led government believes in "first messing up the entire investigation" and then say there is no case.

BJP claimed that Quattrochi is very close to the Gandhi family and posed some questions to Singh and Congress President Sonia Gandhi.

"When UPA came to power the then Additional Solicitor General B Dutta went to London in January 2006 and falsely represented before the authorities that no case is pending against Quattrocchi and the account be de-freezed. It was done accordingly and huge amount of taxpayers' money was withdrawn.

Under whose pressure this was done?" Prasad said.

He alleged that "collusive legal advise" for this was given under the supervision of then Law Minister Hansraj Bhardwaj.

Every effort was made by the Congress to scuttle the investigations and save Quattrrochi, he said.